Energy conservation measures are taken for a typical image forming apparatus, such as a printer, or a multi-function peripheral (MFP). For example, if the image forming apparatus is unused for a specified time, it may shift to an energy conservation state (referred to below as the sleep mode). If the image forming apparatus shifts to the sleep mode, however, it may take time until the image forming apparatus shifts back to a state in which the user can use it (the state will be referred to below as the normal mode).